// $Id: pipe2.c,v 1.1 2004-12-16 08:24:46+09 kaiya Exp kaiya $
#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>

main(int argc, char* argv[]){
int pipes[2];
pid_t pid;

	if(argc<1) exit(3);
	if(pipe(pipes)<0) exit(1);

	if((pid=fork())==0){ // in child
		close(pipes[0]); // close read
		close(1);
		dup(pipes[1]);
		execl("/bin/ps", "ps", "-ef", NULL);
	}else if(pid>0){ // in parent
		close(pipes[1]); // close write
		close(0);
		dup(pipes[0]);
		execl("/bin/grep", "grep", argv[1], NULL);
	}else{
		exit(2);
	}
}